The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Virginie Zeninari - One of the best experts on this subject based on the ideXlab platform.
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upgrading a Laser based spectrometer for the mapping of gas phase co 2 in the headspace of champagne glasses
European Quantum Electronics Conference, 2019Co-Authors: Bertrand Parvitte, Clara Cilindre, A.-l. Moriaux, Gerard Ligerbelair, Raoul Vallon, Virginie ZeninariAbstract:The Laser group of the Groupe de Spectrometrie Moleculaire et Atmospherique (GSMA, Reims, France) has developed various Laser Spectrometers for the study of the atmospheres [1]. Based on this technology we developed the same type of instrument for enological studies conducted by the Effervescence team of GSMA. A diode Laser detection system for the measurements of gas-phase carbon dioxide (CO 2 ) above a glass of bubbly drink such as champagne has been designed [2]. In champagne and sparkling beverages in general, the progressive desorption of CO 2 dissolved in the liquid phase is responsible for bubble formation. Moreover, dissolved CO 2 may also escape by diffusion at the air-champagne interface. A first step in the understanding of the role of CO 2 was to precisely measure its concentration above champagne glasses, under standard tasting conditions [3]. To address this purpose, many optimizations of the set-up have been realized. First the original 2.68 μm diode Laser was coupled to an optical fibre to prevent from atmospheric CO 2 interferences. Then, a second Laser emitting around 2 μm was adapted to realize measurements with large concentrations of CO 2 . Finally, the whole set-up, namely the CO 2 -DLS, was driven by a LabView ® program in order to automatically record the temporal evolution of gas-phase CO 2 concentration in one position of the headspace above liquid [4]. A set of data showing the impact of champagne temperature and volume as well as the intensity of effervescence on the release of gas phase CO 2 was realized [5].
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alternative method for gas detection using pulsed quantum cascade Laser Spectrometers
Optics Letters, 2009Co-Authors: Bruno Grouiez, Bertrand Parvitte, Lilian Joly, Virginie ZeninariAbstract:Pulsed quantum-cascade-Laser (QCL) Spectrometers are usually used to detect atmospheric gases with either the interpulse technique (short pulses, typically 5-20 ns) or the intrapulse technique (long pulses, typically 500-800 ns). Each of these techniques has many drawbacks, which we present. Particularly the gas absorption spectra are generally distorted. We demonstrate the possibility to use intermediate pulses (typically 50-100 ns) for gas detection using pulsed QCL Spectrometers. IR spectra of ammonia recorded in the 10 μm region are presented in various conditions of pulse emission. These experiences demonstrate the large influence of the pulse shape on the recorded spectrum and the importance to use our alternative method for gas detection with pulsed QCL Spectrometers.
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Laboratory spectroscopic calibration of infrared tunable Laser Spectrometers for the in situ sensing of the Earth and Martian atmospheres
Applied Physics B - Laser and Optics, 2006Co-Authors: Virginie Zeninari, Bertrand Parvitte, L. Joly, T. Le Barbu, N. Amarouche, Georges DurryAbstract:This paper reports the laboratory spectroscopic calibration of near- and mid- infrared tunable Laser Spectrometers used to determine in situ trace gases in the middle atmosphere of the Earth or in development for the investigation of the Martian atmosphere. The use of infrared absorption spectroscopy to measure gas concentrations requires a proper knowledge of the rotation–vibration spectra of the targeted molecules as well as a proper investigation of the tunable Laser spectral emission properties. This last point is of particular importance for the use of new-generation Lasers like quantum-cascade Lasers or room-temperature multi-quantum wells Laser diodes emitting between 2 and 3 μm. Purposely, we have developed various laboratory tunable Laser set-ups to obtain accurate line strengths and pressure-broadening coefficients of atmospheric molecules and to test the performances of cutting-edge Laser technology for trace gas sensing. In this paper, the spectroscopic calibration work is described. Several atmospheric applications of tunable Laser are reported to stress the impact on concentration retrieval of a proper spectroscopic calibration work.
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pressure broadening coefficients and line strengths of h2o near 1 39μm application to the in situ sensing of the middle atmosphere with balloonborne diode Lasers
Journal of Quantitative Spectroscopy & Radiative Transfer, 2005Co-Authors: Georges Durry, Bertrand Parvitte, Virginie Zeninari, Le T Barbu, F Lefevre, J Ovarlez, R R GamacheAbstract:Abstract Since 1998, we have developed two balloonborne diode Laser Spectrometers, SDLA and micro-SDLA, to yield in situ concentration data of H2O in the middle atmosphere by absorption spectroscopy in the 1.39-μm spectral range. In this paper, we revisit the molecular parameters, line intensities and pressure-broadening coefficients, for several lines of the ν1+ν3 and 2ν1 bands, which are useful for the monitoring of atmospheric H2O. The new values are thoroughly compared to existing molecular database and previous determinations. Calculations are performed to yield the pressure-effect coefficients: the theoretical model is described and the ab initio predictions are compared to laboratory measurements achieved with a Laser diode spectrometer. The improvement in the H2O monitoring obtained with the new set of molecular data is evaluated directly from vertical H2O concentration profiles.
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differential helmholtz resonant photoacoustic cell for spectroscopy and gas analysis with room temperature diode Lasers
Applied Physics B, 2002Co-Authors: Kyuseok Song, Bertrand Parvitte, H K Cha, V A Kapitanov, Yu N Ponomarev, A P Rostov, D Courtois, Virginie ZeninariAbstract:The results of theoretical and experimental studies and the design of a multi-purpose differential Helmholtz resonant photoacoustic detector (DHRD) and its applications to high-resolution spectroscopy of molecular gases and gas analysis with a room-temperature diode Laser in the near-IR region are summarized. The series of experiments and numerical analysis of the DHRD sensitivity were performed for both types (single-pass and multi-pass) of DHRDs within a wide pressure range 0.1–101 kPa, including the regime of a gas flowing through a DHRD cell. The hardware and electronic arrangement of DHRDs for diode Laser Spectrometers and gas analyzers providing a limiting absorption sensitivity better than 10-7 Wm-1 are described. The results of measurements of spectral line parameters of H2O near 800 and 1390 nm and CH4 near 1650 nm (intensities, line broadening and shifting by atomic and molecular gases) are presented and discussed. The problems and the ways of perfection of the methodology and accuracy of DHRD techniques with tunable diode Lasers of near-IR and visible spectral ranges are discussed.
Bertrand Parvitte - One of the best experts on this subject based on the ideXlab platform.
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upgrading a Laser based spectrometer for the mapping of gas phase co 2 in the headspace of champagne glasses
European Quantum Electronics Conference, 2019Co-Authors: Bertrand Parvitte, Clara Cilindre, A.-l. Moriaux, Gerard Ligerbelair, Raoul Vallon, Virginie ZeninariAbstract:The Laser group of the Groupe de Spectrometrie Moleculaire et Atmospherique (GSMA, Reims, France) has developed various Laser Spectrometers for the study of the atmospheres [1]. Based on this technology we developed the same type of instrument for enological studies conducted by the Effervescence team of GSMA. A diode Laser detection system for the measurements of gas-phase carbon dioxide (CO 2 ) above a glass of bubbly drink such as champagne has been designed [2]. In champagne and sparkling beverages in general, the progressive desorption of CO 2 dissolved in the liquid phase is responsible for bubble formation. Moreover, dissolved CO 2 may also escape by diffusion at the air-champagne interface. A first step in the understanding of the role of CO 2 was to precisely measure its concentration above champagne glasses, under standard tasting conditions [3]. To address this purpose, many optimizations of the set-up have been realized. First the original 2.68 μm diode Laser was coupled to an optical fibre to prevent from atmospheric CO 2 interferences. Then, a second Laser emitting around 2 μm was adapted to realize measurements with large concentrations of CO 2 . Finally, the whole set-up, namely the CO 2 -DLS, was driven by a LabView ® program in order to automatically record the temporal evolution of gas-phase CO 2 concentration in one position of the headspace above liquid [4]. A set of data showing the impact of champagne temperature and volume as well as the intensity of effervescence on the release of gas phase CO 2 was realized [5].
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alternative method for gas detection using pulsed quantum cascade Laser Spectrometers
Optics Letters, 2009Co-Authors: Bruno Grouiez, Bertrand Parvitte, Lilian Joly, Virginie ZeninariAbstract:Pulsed quantum-cascade-Laser (QCL) Spectrometers are usually used to detect atmospheric gases with either the interpulse technique (short pulses, typically 5-20 ns) or the intrapulse technique (long pulses, typically 500-800 ns). Each of these techniques has many drawbacks, which we present. Particularly the gas absorption spectra are generally distorted. We demonstrate the possibility to use intermediate pulses (typically 50-100 ns) for gas detection using pulsed QCL Spectrometers. IR spectra of ammonia recorded in the 10 μm region are presented in various conditions of pulse emission. These experiences demonstrate the large influence of the pulse shape on the recorded spectrum and the importance to use our alternative method for gas detection with pulsed QCL Spectrometers.
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Laboratory spectroscopic calibration of infrared tunable Laser Spectrometers for the in situ sensing of the Earth and Martian atmospheres
Applied Physics B - Laser and Optics, 2006Co-Authors: Virginie Zeninari, Bertrand Parvitte, L. Joly, T. Le Barbu, N. Amarouche, Georges DurryAbstract:This paper reports the laboratory spectroscopic calibration of near- and mid- infrared tunable Laser Spectrometers used to determine in situ trace gases in the middle atmosphere of the Earth or in development for the investigation of the Martian atmosphere. The use of infrared absorption spectroscopy to measure gas concentrations requires a proper knowledge of the rotation–vibration spectra of the targeted molecules as well as a proper investigation of the tunable Laser spectral emission properties. This last point is of particular importance for the use of new-generation Lasers like quantum-cascade Lasers or room-temperature multi-quantum wells Laser diodes emitting between 2 and 3 μm. Purposely, we have developed various laboratory tunable Laser set-ups to obtain accurate line strengths and pressure-broadening coefficients of atmospheric molecules and to test the performances of cutting-edge Laser technology for trace gas sensing. In this paper, the spectroscopic calibration work is described. Several atmospheric applications of tunable Laser are reported to stress the impact on concentration retrieval of a proper spectroscopic calibration work.
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pressure broadening coefficients and line strengths of h2o near 1 39μm application to the in situ sensing of the middle atmosphere with balloonborne diode Lasers
Journal of Quantitative Spectroscopy & Radiative Transfer, 2005Co-Authors: Georges Durry, Bertrand Parvitte, Virginie Zeninari, Le T Barbu, F Lefevre, J Ovarlez, R R GamacheAbstract:Abstract Since 1998, we have developed two balloonborne diode Laser Spectrometers, SDLA and micro-SDLA, to yield in situ concentration data of H2O in the middle atmosphere by absorption spectroscopy in the 1.39-μm spectral range. In this paper, we revisit the molecular parameters, line intensities and pressure-broadening coefficients, for several lines of the ν1+ν3 and 2ν1 bands, which are useful for the monitoring of atmospheric H2O. The new values are thoroughly compared to existing molecular database and previous determinations. Calculations are performed to yield the pressure-effect coefficients: the theoretical model is described and the ab initio predictions are compared to laboratory measurements achieved with a Laser diode spectrometer. The improvement in the H2O monitoring obtained with the new set of molecular data is evaluated directly from vertical H2O concentration profiles.
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differential helmholtz resonant photoacoustic cell for spectroscopy and gas analysis with room temperature diode Lasers
Applied Physics B, 2002Co-Authors: Kyuseok Song, Bertrand Parvitte, H K Cha, V A Kapitanov, Yu N Ponomarev, A P Rostov, D Courtois, Virginie ZeninariAbstract:The results of theoretical and experimental studies and the design of a multi-purpose differential Helmholtz resonant photoacoustic detector (DHRD) and its applications to high-resolution spectroscopy of molecular gases and gas analysis with a room-temperature diode Laser in the near-IR region are summarized. The series of experiments and numerical analysis of the DHRD sensitivity were performed for both types (single-pass and multi-pass) of DHRDs within a wide pressure range 0.1–101 kPa, including the regime of a gas flowing through a DHRD cell. The hardware and electronic arrangement of DHRDs for diode Laser Spectrometers and gas analyzers providing a limiting absorption sensitivity better than 10-7 Wm-1 are described. The results of measurements of spectral line parameters of H2O near 800 and 1390 nm and CH4 near 1650 nm (intensities, line broadening and shifting by atomic and molecular gases) are presented and discussed. The problems and the ways of perfection of the methodology and accuracy of DHRD techniques with tunable diode Lasers of near-IR and visible spectral ranges are discussed.
David C Wilson - One of the best experts on this subject based on the ideXlab platform.
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time dependent measurements of nitrous oxide and carbon dioxide collisional relaxation processes by a frequency down chirped quantum cascade Laser rapid passage signals and the time dependence of collisional processes
Journal of Chemical Physics, 2010Co-Authors: Nicola Tasinato, Kenneth G Hay, N Langford, G Duxbury, David C WilsonAbstract:Intrapulse quantum cascade Laser Spectrometers are able to produce both saturation and molecular alignment of the gas sample. This is due to the rapid sweep of the radiation through the absorption features. The intrapulse time domain spectra closely resemble those recorded in coherent optical nutation experiments. In the present paper, the frequency down-chirped technique is employed to investigate the nitrous oxide–foreign gas collisions. We have demonstrated that the measurements may be characterized by the induced polarization dominated and collision dominated measurement limits. The first of these is directly related to the time dependence of the long range collision cross sections. Among the collisional partners considered, carbon dioxide shows a very unusual behavior of rapid polarization damping, resulting in the production of symmetrical line shapes at very low gas buffer pressures. In the collision dominated regime, the pressure broadening parameters, which we have derived, are comparable at slow...
Siamak Forouhar - One of the best experts on this subject based on the ideXlab platform.
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miniature tunable Laser Spectrometers for quantifying atmospheric trace gases water resources earth back contamination and in situ resource utilization
Concepts and Approaches for Mars Exploration Lunar and Planetary Institute, 2012Co-Authors: C R Webster, Didier Keymeulen, Gregory J Flesch, L E Christensen, Siamak ForouharAbstract:The Tunable Laser Spectrometers (TLS) technique has seen wide applicability in gas measurement and analysis for atmospheric analysis, industrial, commercial and health monitoring and space applications. In Earth science using balloons and aircraft over 2 decades, several groups (JPL, NASA Langley & Ames, NOAA, Harvard U., etc) have demonstrated the technique for ozone hole studies, lab kinetics measurements, cloud physics and transport, climate change in the ice record. The recent availability of high-power (mW) room temperature Lasers (TDL, IC, QC) has enabled miniaturized, high-sensitivity Spectrometers for industry and space (1) Mars, Titan, Venus, Saturn, Moon (2) Commercial isotope ratio Spectrometers are replacing bulkier, complex isotope ratio mass Spectrometers.
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low power consumption Laser for next generation miniature optical Spectrometers for trace gas analysis
SPIE Photonic West, 2011Co-Authors: Siamak Forouhar, Clifford Frez, K J Franz, A Ksendzov, Yueming Qiu, K A Soibel, J Chen, T Hosoda, G Kipshidze, L ShterengasAbstract:The air quality of any manned spacecraft needs to be continuously monitored in order to safeguard the health of the crew. Air quality monitoring grows in importance as mission duration increases. Due to the small size, low power draw, and performance reliability, semiconductor Laser-based instruments are viable candidates for this purpose. Achieving a minimum instrument size requires Lasers with emission wavelength coinciding with the absorption of the fundamental absorption lines of the target gases, which are mostly in the 3.0-5.0 mu m wavelength range. In this paper we report on our progress developing high wall plug efficiency type-I quantum-well GaSb-based diode Lasers operating at room temperatures in the spectral region near 3.0-3.5 mu m and quantum cascade (QC) Lasers in the 4.0-5.0 mu m range. These Lasers will enable the development of miniature, low-power Laser Spectrometers for environmental monitoring of the spacecraft
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The MVACS tunable diode Laser Spectrometers
Journal of Geophysical Research: Planets, 2001Co-Authors: Randy D. May, Siamak Forouhar, David Crisp, W. Stephen Woodward, David A. Paige, Asmin V. Pathare, William V. BoyntonAbstract:Two independent tunable diode Laser Spectrometers are resident aboard the Mars Polar Lander as part of the Mars Volatiles and Climate Surveyor payload. One spectrometer is located on the meteorological mast for measurements of H2O and CO2 in the free atmosphere, and the other serves as the H2O and CO2 analyzer for the Thermal and Evolved Gas Analyzer. Water vapor is measured using a tunable diode Laser operating at 1.37 μm, while CO2 is measured using a second Laser operating near 2.05 μm. The 2.05 μm Laser also has isotopic analysis capability. In addition to the major CO2 isotopomer (12C16O16O), analyses of 13C16O16O and 12C18O16O in the atmosphere and in the Thermal and Evolved Gas Analyzer are possible under certain conditions. The Spectrometers were designed and built at the Jet Propulsion Laboratory and have their heritage in a series of tunable diode Laser Spectrometers developed for Earth atmospheric studies using high-altitude aircraft and balloon platforms. The 1.37 μm diode Laser on the meteorological mast will provide the first in situ measurements of water vapor in the Martian boundary layer, with a detection sensitivity an order of magnitude greater than the water vapor abundances inferred from the remote-sensing observations by the Viking Orbiters.
Werner Eugster - One of the best experts on this subject based on the ideXlab platform.
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flux correction for closed path Laser Spectrometers without internal water vapor measurements
Atmospheric Measurement Techniques Discussions, 2012Co-Authors: Rebecca Hiller, C Zellweger, Alexander Knohl, Werner EugsterAbstract:Abstract. Recently, instruments became available on the market that provide the possibility to perform eddy covariance flux measurements of CH4 and many other trace gases, including the traditional CO2 and H2O. Most of these instruments employ Laser spectroscopy, where a cross-sensitivity to H2O is frequently observed leading to an increased dilution effect. Additionally, sorption processes at the intake tube walls modify and delay the observed H2O signal in closed-path systems more strongly than the signal of the sampled trace gas. Thereby, a phase shift between the trace gas and H2O fluctuations is introduced that dampens the H2O flux observed in the sampling cell. For instruments that do not provide direct H2O measurement in the sampling cell, transfer functions from externally measured H2O fluxes are needed to estimate the effect of H2O on trace gas flux measurements. The effects of cross-sensitivity and the damping are shown for an eddy covariance setup with the Fast Greenhouse Gas Analyzer (FGGA, Los Gatos Research Inc.) that measures CO2, CH4, and H2O fluxes. This instrument is technically identical with the Fast Methane Analyzer (FMA, Los Gatos Research Inc.) that does not measure H2O concentrations. Hence, we used measurements from a FGGA to derive a modified correction for the FMA accounting for dilution as well as phase shift effects in our instrumental setup. With our specific setup for eddy covariance flux measurements, the cross-sensitivity counteracts the damping effects, which compensate each other. Hence, the new correction only deviates very slightly from the traditional Webb, Pearman, and Leuning density correction, which is calculated from separate measurements of the atmospheric water vapor flux.
